http://www.unicorn-computer.com.tw/products/itx/2794a.html
That's the motherboard so far as I can tell, unfortunately they don't list the cable in their accessories on the site and I'm pretty sure it's proprietary; I've not seen another cable like it.
I don't know what your problem is with it but I suggest you save the motherboard connector and splice it into something useful yourself. You can get a terminal block at any hardware store that'll let you join cable to cable so you won't have to fiddle with the connectors at all.